// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_GL_GL_SHARE_GROUP_H_
#define UI_GL_GL_SHARE_GROUP_H_

#include <set>

#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "build/build_config.h"
#include "ui/gl/gl_export.h"

namespace gfx {

class GLContext;

// A group of GL contexts that share an ID namespace.
class GL_EXPORT GLShareGroup : public base::RefCounted<GLShareGroup> {
public:
    GLShareGroup();

    // These two should only be called from the constructor and destructor of
    // GLContext.
    void AddContext(GLContext* context);
    void RemoveContext(GLContext* context);

    // Returns a handle to any initialized context in the share group or NULL if
    // there are no initialized contexts in the share group.
    void* GetHandle();

    // Returns a pointer to any initialized context in the share group
    // or NULL if there are no initialized contexts in the share group.
    GLContext* GetContext();

    // Sets and returns the unique shared GL context. Used for context
    // virtualization.
    void SetSharedContext(GLContext* context);
    GLContext* GetSharedContext();

#if defined(OS_MACOSX)
    // Sets and returns the ID of the renderer that all contexts in this share
    // group should be on.
    void SetRendererID(int renderer_id);
    int GetRendererID();
#endif

private:
    friend class base::RefCounted<GLShareGroup>;

    ~GLShareGroup();

    // References to GLContext are by raw pointer to avoid a reference count
    // cycle.
    typedef std::set<GLContext*> ContextSet;
    ContextSet contexts_;

    GLContext* shared_context_;

#if defined(OS_MACOSX)
    int renderer_id_;
#endif

    DISALLOW_COPY_AND_ASSIGN(GLShareGroup);
};

} // namespace gfx

#endif // UI_GL_GL_SHARE_GROUP_H_
